1. Field of the Invention
The present invention relates to a substrate type antenna configured on a thin substrate.
2. Description of the Related Art
As a conventional substrate type antenna of this type, there has been known a configuration which has a substrate made of a dielectric material, a loop-like first coupled-portion or joint pattern formed at a first substrate surface of the substrate and divided at one spot thereof, and a loop-like second joint pattern formed at a second substrate surface of the substrate and divided at one spot, and in which electrostatic capacitively-coupled and magnetic inductively-coupled states are formed between the first joint pattern and the second joint pattern (refer to, for example, a patent document 1 (Japanese Patent Application Laid-Open No. 2007-142666)). According to such a configuration, unlike a conventional case in which patterns are formed on the same plane, the electrostatic capacitively-coupled and magnetic inductively-coupled states between the patterns by the substrate are greatly improved, and a high-frequency coupler excellent in transmission characteristic in a wide frequency band as compared with the conventional one can easily be obtained.
In the conventional substrate type antenna, however, its configuration increases in complexity if one attempts to achieve a further gain improvement by a combination of a plurality of antennas.